Remove unnecessary refreshCastButtonVisibility call

third_party/WebKit/LayoutTests/media/controls-overlay-cast-button.html

Index: third_party/WebKit/LayoutTests/media/controls-overlay-cast-button.html
diff --git a/third_party/WebKit/LayoutTests/media/controls-overlay-cast-button.html b/third_party/WebKit/LayoutTests/media/controls-overlay-cast-button.html
index d3a019e0f33c43fd4eb57223b9b8ad1c875b7bc9..6847192e254e83b7eb059bae1ed25f571e602a14 100644
--- a/third_party/WebKit/LayoutTests/media/controls-overlay-cast-button.html
+++ b/third_party/WebKit/LayoutTests/media/controls-overlay-cast-button.html
@@ -34,13 +34,5 @@ async_test(function(t) {
         internals.mediaPlayerRemoteRouteAvailabilityChanged(video, false);
         assert_equals(button.style.display, "none", "button should not be visible after cast device goes away");
     });
-
-    function overlayCastButton(element) {
-        var controlID = "-internal-media-controls-overlay-cast-button";
-        var button = mediaControlsElement(internals.shadowRoot(element).firstChild, controlID);
-        if (!button)
-            throw "Failed to find cast button";
-        return button;
-    }
 });
-</script>
+</script>